The Shimano CS-M5100 is the cassette for the DEORE 11-speed group. The distinctively designed HYPERGLIDE sprockets incorporate specially positioned shift ramps and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result. The HG cassette sprocket, which was developed for 11-speed system, underwent comprehensive optimization to achieve super-highly efficient shifting. Ride anywhere with smooth and precise HG shifting Optimized gear combination and gear ratio 11-51T wide gear range 11-42T close gear step Series: Deore 11-speed Range: choose; 11/42t (11-13-15-17-19-21-24-28-32-37-42T); 11/51t (11-13-15-18-21-24-28-33-39-45-51T) Cassette/Freehub Compatibility: Shimano HG